Trigonometry

Radians intuition

The circumference formula is , but in the unit circle , so the whole circumference is .

Pythagorean trigonometric identity

Since the hypotenuse/radius is 1, we can use the pythagorean theorem like this:

HUGE HINT ABOUT IDENTITY FUNCTIONS

Basically, if you look at the functions and , you will notice that they are the same, just shifted.
So if you look at the unit cicle, you can easily figure them out without memorizing them.

Values of sin & cos at various angles

Trigonometric functions

Exercises

Example